Yearly Archives: 2009

Opinion

The Future of Tree-based Science Knowledge

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Is Grim. What Replaces It?

I had lunch and dinner recently with former colleagues of mine back from when I worked at Sky & Telescope. The topic of conversation came around (as it usually does) to the fact that tree-based dissemination of knowledge (via magazines and newspapers) is giving way to knowledge being made available via electronic means (Web, Internet, etc.).  This is causing all sorts of changes in the print/info industry, not all of it good. I know that S&T, for example, has downsized its staff (or rather, the parent corporation that owns S&T is ordering those downsizes), and that similar layoffs are occurring at newspapers and magazines everywhere. I have to assume that this is because of a number of factors: migration of advertisers to online business models, migration of readers to online sources of information, cost of labor (money to pay writers and editors for print publications), and cost of equipment and buildings to maintain print products.  In short, money’s tight, people and equipment cost a lot, and it’s often cheaper to put the news out online. How you make money from that is the big question that I suspect gets rocketed around the executive suites of news organizations a lot.

At our place we decided that we didn’t need to get a daily newspaper, so we stopped getting it. We still get a few magazines, but have cut those back quite a bit, too.  Because I’m a science writer, I already have many, many good sources of information online, and don’t need to get print subscriptions to journals (I have electronic subscriptions).  In short, I get a lot of my news online and rely on fewer print pubs to give me more in-depth looks.

I thought about all this when I got the news that another friend got laid off from a job as a science writer at a magazine. I notice that science writers in general have been getting the boot a lot.  For example, Miles O’Brien was summarily shoved out at CNN (thus depriving the network of a good, qualified science writer/reporter).  What sort of message do these layoffs send to other writers? To the public?  That science isn’t important enough to be covered? That years of experience in science writing isn’t worthy of treasuring in a news organization?  (But sports ad nauseum, politics up the wazoo, opinion columns that are sometimes thinly disguised propaganda for political or business interests, and bra and panty ads are more necessary to a modern civilization than an understanding of the technology and science we use every day?)

For the sake of our societies as well as the science writers whose collective wisdom is being thrown on the junkheap of progress, I hope that as we move to an electronic-based information model, some of the people who are now being left in the dust as print media collapses will bring their voices online.  We can’t afford to lose them.

astronomy, astronomy media, t leporis

Aperture Fever

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Slaking the Thirst for Bigger Mirrors

Sometimes astronomers come down with a peculiar condition called Aperture Fever. In short, no matter what size their telescope mirror is, they always want a bigger one.  But, there’s a limit to the size of mirror (or radio dish) you can build and still have it be useful.  You could probably pour a piece of glass 100 meters across, if you wanted to. You could build a huge radio dish, if you wanted to.  But, getting a big piece of glass or a monstrous dish on a support and keeping them from breaking under the pull of gravity (or at the very least, keeping them from distorting and bending due to gravity’s tug on it) would render them useless.

Light collected by three VLT Auxiliary Telescopes, and combined using the technique of interferometry, provides astronomers with vision as sharp as that from a giant telescope with a diameter equal to the largest separation between the telescopes used. To obtain the image of T Leporis using data from the Very Large Telescope Interferometer, astronomers used the four 1.8-metre Auxiliary Telescopes in different configurations to mimic a telescope almost 100 metres in diameter, as represented schematically on this artist’s impression of the Paranal platform
Light collected by three VLT Auxiliary Telescopes, and combined using the technique of interferometry, provides astronomers with vision as sharp as that from a giant telescope with a diameter equal to the largest separation between the telescopes used. To obtain the image of T Leporis using data from the Very Large Telescope Interferometer, astronomers used the four 1.8-metre Auxiliary Telescopes in different configurations to mimic a telescope almost 100 metres in diameter, as represented schematically on this artist’s impression of the Paranal platform

There are some cures for aperture fever, however. The latest was demonstrated in Chile by a group of French astronomers who ganged together all the telescopes at the European Southern Observatory.

Essentially, what the astronomers did was create a 100-meter-wide interferometer — a sort of “virtual” telescope consisting of several smaller (1.8-meter) VLT Auxiliary telescopes. The result was an aperture the size of a much larger telescope. They made several observing runs with this special set-up to collect the light  streaming from their target, and then combined that light into one very fine image.

What makes this use doubly cool is that they used it to create one of the first infrared interferometry observations.  That’s quite a feat.

Their target was the star T Leporis, a type of pulsating star called a Mira variable (named after the star Mira, which is the “prototype” for these kinds of stars).

Mira stars are among the biggest factories of molecules and dust in the universe. T Leporis is a fine example of this activity. It pulsates with a period of 380 days and loses the equivalent of the Earth’s mass in dust and gas every year. Since the molecules and dust get created in the layers of atmosphere surrounding the central star,  astronomers would like to be able to look at these layers in great detail to see how it all happens. But this is no easy task, given that the stars themselves are so far away. Even though we’re talking about a huge star, from a distance of 500 light-years T Leporis appears quite small — about half a millionth of the size of the Sun. This is where interferometry and repeated observing runs can make a huge difference.

The reconstructed image shows this star up-close. It’s 100 times larger than the Sun, and is surrounded by a sphere of gas about three times larger than the star itself. That we can even see this level of detail in a star that lies 500 light-years away shows that aperture fever can be slaked with a virtual telescope and the right amount of observing time.